Electrolytic condenser



Nov. 9, 1937. A. GEORGIEV 2,098,745

ELECTROLYT IC CONDENS ER Filed Sept. 2, 1932 2 Sheets-Sheet l ATTORNEYSA. GEORGIEV 2,098,745

ELECTROLYTIC CONDENSER I Filed Sept. 2, 1952 2 Sheets-Sheet 2 Nov. 9,1937.

Patented Nov. 9 1937 UNITED STATES PATENT OFFICE I 2,098,745ELECTROLYTIC coNnnNsEn Alexander Georgiev, Brooklyn, N. Y., asaignor toQeravox Corporation, a corporation of New or Application September 2,1932, Serial No. 631,479

12 Claims. (01. 175-315), My present invention relates to electrolyticment of the composite interlay comprises a sheet cells, more especiallyto electrolytic condensers. ll of gauze, which may be of mesh 40 x 44,and An object of the invention is to provide a conthe additional elementcomprises a sheet l of denser of the above type capable of use oncirclose-texture paper. cuits of even 500 volts or more, which, thoughIn a preferred embodiment as shown on en-- 5 the constituent partsthereof are closely pressed larged scale in Fig. 2, each of the aluminumelectogether for compactness, is yet substantially trode foils may be inthe order of .001" in thickproof against short-circuit. ness, the gauze.006 in thickness and the paper Another object is to provide a condenserof interlay .0004" to .0005" in thickness. the above type which shall beadapted to the use Since in practice the anode is formed with a 10 ofextremely thin metal foil electrodes of thickdielectric film on bothfaces thereof, it is prenessin the order of .001inch. ferred to place alayer of gauze H in contact Another object is to provide a condenser ofwith the outer surface of the anode, and superthe above type, so compactin construction as pose over the latter a layer of paper I5, similar 15to render it suitable for use in the limited space to layers H and I5respectively. The anode foil 15 afforded in modern radio receiving sets.is thus sandwiched between two layers of gauze In the accompanyingdrawings in which are in which electrolyte is absorbed, and these layersshown one or more of various possible embodiof gauze with theintervening foil are in turn ments of the several features of theinvention, sandwiched between two layers of paper.

iii

Fig. 1 is a perspective view showing the elec By the use of materials ofthe small thickness 20 trodes and interlay in coordinated relation butset forth, a condenser of relatively tremendous before W electrode areacan be produced in an extremely Fig. 2 is a' cross-sectional view online 2-2 small volume. oi! Fig. 1, showing the thickness in greatly en-It is preferred to use as the electrolyte a solularg d p vp ns; tion ofthe general character of those described 25 Fig. 3 is a perspective viewof the finished and in my prior patent, No. 1,815,768 of July 21,enrolled condenser; 1931. Such solution is essentially liquid in'char-Fig. 4 isa sectional view showing one typical acter and becomes readilyabsorbed in the gauze enclosure and terminal arrangement for theconinterlay l4 and will also permeate the close tex- 39 denser; and.ture paper interlay element l5, so that the con- Fig. 5 is a viewsimilar to Fig. 2 of a modified duotivity between the electrodes is notadversely formaffected by the presence of the paper and the Referringnow to the drawings there is shown gauze. in Figs. 1 and 2 a cathodefoil I 0 which is an Where extremely thin foils in the order of 3-5elongated strip of aluminum and a similar'foii .001" are used, theterminal tabs i2 and I3 II also of aluminum and serving as the anode.would be so weak as to require extremely careful These 10116 y beSimilar in a a ter t0 handling to guard against tearing the samedurthose (11801056411111 y Prior Patent, 9, ing assembly of thecondenser in the can or granted July 20, 1931, though a preferred (2011-other cgntainer, Accordingly these tabs are restructibn and arrangementof terminal tab inforced in manner shown and claimed in my 40 of theanode foil and of terminal tab 13 of the comendmg application, serial 59 92 filed cathode foil will be more fully described below. October 2313,33" lustmtively I have shown in The interlay between the foilsiscomposite and the present emzmiment & Strip 5 f thicker includes alayerof relatively open-texture fibrous ammmm gram. extending acmss part Qfthe 4;} material having high absorptive fiamsity for the of the ca thodefoil and riveted thereto as i j? n'yje i -a}? "5 ,rativeii'" @132 inthicknew, m" 52 formed a end,

other functions, and with the cathode and anode tabs protruding from thetop.

' In use, the paper absorbs but a small proportion of the electrolyte,the great bulk of which is absorbed by the gauze. The paper howeverabsorbs suflicient of the electrolyte not to disturb the conductivitybetween the film on the anode and the metal of the cathode.

It is understood that the invention is not lim ited to the use ofelectrodes of extreme thinness or to the use of a paper interlay elementof extreme thinness, but in its broader aspects the invention embracesthe use of an electrolyte-holding interlay with special protectivemeans, whether of paper or other material, whether separate orincorporated as an integral part of the open texture or gauze interlayand which without objectionably interfering with the conductivity ofelectrolyte between the two electrodes yet effectively prevents ashort-circuit under the usual short-circuit-producing conditions throughthe open mesh of the gauze.

In present commercial practice I use an aluminum anode foil of .002" inthickness and aluminum cathode foil .0015" in thickness.

The roll may be encased in any of various conventional manners either ina paper box, but preferably in an aluminum can as in my prior Patent No.1,789,949. Illustratively I have shown in Fig. 4 one mode of enclosingthe condenser coil, which mode in itself is not part of the inventionclaimed herein. It is briefly noted that the formed roll with theelectrolyte absorbed is enclosed in a can 22 without any furtherfilling, the can being sealed at its top as by pitch iii, resting on afalse top 2%, and the terminals i and t riveted respectively to thecathode and anode foil tabs l2 and it protrude from the upper end of thecondenser.

Preferably a vent structure is provided as in the bottom of the can,including a plug of cork 25 frictionally fitting into an inturnedopening 26, which cork serves as a safety plug to relieve any excessivegas pressure evolved in operation of the condenser. The cork plug doespermit the accumulation of some gas pressure within the container duringoperation. This pressure is deof the electrolyte substantially constantthroughout operation, thus avoiding the variation in performance of thecondenser otherwise incurred.

The vent structure is not claimed herein but is covered in my co-pendingapplication Serial No. 576,473, filed November 21, 1931, now Patent No.2,006,713.

It is noted that where the condenser has merely a single gauze interlaywithout the thin paper or equivalent protective agency, there is agreatly increased likelihood of short-circuit. Any im= perfection of thefoil, such as a wrinkled, sharp, ragged edge or other irregularity, mayreadily penetrate one or more of the meshes of the gauze. Anyimperfection of the gauze itself may permit a direct contact between thetwo electrodes. Even where the gauze is in good condition, the tightwinding of the electrodes to produce compactness of the structure mightbring the foils so close together at one or-more of the meshes of thegauze as to lead to short-circuit.

While an electrolytic condenser with a single gauze interlay willfunction as long as the conditions of operation are ideal or nearlyideal,

.and power factor.

aoeavae departure from such condition of operation may lead toshort-circuit, especially under high voltage operation. The use of theauxiliary paper interlay imparts to the condenser a high factor ofsafety under abnormal conditions of operation.

A condenser with two layers of gauze, while less subject toshort-circuit than a unit with. only a single layer of gauze, presentsconsiderably more bulk as is immediately obvious, involves greater costand does not lend itself so readily to the use of the extremely thinfoil which is preferably employed. A thin foil more readily developswrinkles which may establish a direct contact between the two electrodeswhen gauze is used, while paper of close texture prevents such contacteven though the foils be wrinkled.

Where the condenser is intended for particularly high voltage and othersevere operating conditions, rendering desirable a greater spacingbetween the electrodes and a supply of liquid electrolyte of greatervolume than a single gauze can store, it is preferred to employ a doublelayer of gauze as best shown in Fig. 5, however with a thin sheet ofpaper between the two layers oi gauze. In the cross-sectional view ofFig. 5 the electrodes are shown at 21 and 28, the two layers ofintervening gauze at 29 and 3d, and the intermediate layer of paper at3E. The double layer of gauze at the other face of the anode appears atin and 35, and the layer of paper intervening between said gauze layers,at. 3i.

An interlay of paper alone without gauze has not been found assatisfactory as the use of gauze combined with paper, because such paperdoes not absorb enough electrolyte solution to insure long life to thecondenser and dependable capacity When subjected to the fairly hightemperature of 120 to 140 F. frequently incurred in use of the condenserin radio receiving sets, the capacity would drop and the equivalentseries resistance would rise due to loss of moisture from theelectrolyte.

It will thus be seen that there is herein described apparatus in whichthe several features of this invention are embodied, and which apparatusin its action attains the various objects of the invention and is wellsuited to meet .the requirements of practical use.

As many changes could be made in the above construction, and manyapparently widely different embodiments of this invention could be madewithout departing from the scope thereof, it is intended that all mattercontained in the above description or shown in the accompanying drawingsshall be interpreted as illustrative and not in' a limiting sense.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is:--

1. An electrolytic condenser comprising electrodes and a compositefibrous interlay interposed therebetween, said interlay including twosuperposed elements,'one of relatively open mesh and highelectrolyte-absorptive capacity and the other of close texture and lowerelectrolyte-absorptive capacity.

2. An electrolytic condenser comprising electrodes, a composite fibrousinterlay interposed 1 therebetween and including superposed elements,

permeable to electrolyte, engaging one of said electrodes andsubstantially preventing engagement between said electrode and saidgauze.

4. An electrolytic condenser comprising electrodes and a compositefibrous interlay therebetween including a layer of gauze and a layer ofthin paper of close texture.

5. An electrolytic condenser comprising superposed electrodes, a fibrousinterlay therebetween, said electrodes and interlay enrolled to form aconvolute unit, said interlay including two layers, one of relativelyopen mesh and higher electrolyte-absorptive capacity, the other of closetexture and lower electrolyte-absorptive capacity.

6. An electrolytic condenser including elongated cathode and anodefoils, an interposed layer of gauze, said elements enrolled to form aconvolute condenser structure and means interposed between the gauzelayer and one of said foils, pervious to electrolyte, and substantiallypreventing protrusion of the contiguous foil through any part of thegauze.

'7. An electrolytic condenser comprising an anode foil, a layer of.gauze and a layer of paper on one face of the anode, a similar layer ofgauze and layer of paper on the other face of the anode, and a cathodefoil, all insuperposed relationship, said elements enrolled to form aconvolute condenser structure.

8. An electrolytic condenser comprising electrodes of thickness in theorder of .001, an interposed composite fibrous interlay including alayer of relatively open texture having relatively highelectrolyte-absorptive capacity and a layer of close texture paper oflower electrolyte-absorptive capacity and of thickness in the order of.0005".

9. An electrolytic condenser including elon-. gated cathode and anodefoils of thickness each in the order of .001" and composite fibrousinterlays on opposite faces of said anode foil, each comprising afibrous sheet of relatively opentexture and a sheet of paper ofrelatively close texture of thickness in the order of .0005", all ofsaid elements being enrolled to form a convolute unit.

10. An electrolytic condenser including an anode and a cathode ofaluminum foil, each of thickness in the order of .001, composite fibrousinterlays on opposite faces of the anode foil, each including a layer ofrelatively open mesh gauze and a layer of relatively close mesh paper ofthickness in the order of .0005 and an electrolyte absorbed in thecomposite interlay, said electrolyte being of mobile character.

11. An electrolytic condenser comprising an anode foil, electrolyteretaining gauze, covering the faces of said anode foil, paper coveringthe exposed faces of said gauze, and a cathode foil covering the exposedface of the paper at one side.

12. An electrolytic condenser comprising electrodes and a compositeinsulating interlay inter-- posed therebetween, said interlay includingtwo superposed sheet elements, one of relatively high electrolyteabsorptive capacity serving as the major absorbent means for electrolyteand the other of lower electrolyte absorptive capacity serving as aprotective means.

ALEXANDER GEORGIEV.

